Innovations in IPR Desal HORIZONS

Expanding Population, Expanding Capacity

HORIZONSInnovations in IPR

2 Sidestream Treatment Solutions

6 IntegratingDesal

9 13SUMMER 2014

water environment solutions

Reuse, Desal, and theFuture of Water

Blue Planet?

HORIZONS SUMMER 20142

The recent implementation of Ocean Outfall

legislation in Florida has created a groundswell of

reuse master planning and process investigation in

the southeastern portion of the state, as municipalities

must prepare to shut down their ocean outfalls and

reuse 60 percent of the outfalls’ baseline flow for a

beneficial purpose by 2025.

In response to this impending deadline, the City of

Hollywood turned to Hazen and Sawyer to investigate

options for reuse required under the new law. Three

options were initially identified – expanding the public

irrigation system, recharging the Biscayne aquifer, and

recharging the Floridan aquifer. Serving coastal cities with

a high groundwater table, the City’s Southern Regional

Wastewater Treatment Plant (SRWWTP) has a salty

effluent, rendering it unsuitable for irrigation reuse without

reverse osmosis (RO) treatment, and the required piping

network would need to be extended well beyond city limits,

escalating the cost of implementing the mandated reuse

to $1 billion. Effluent going into the Biscayne aquifer, the

predominant source of drinking water for all of southeast

Florida, would require costly microfiltration (MF)/RO/

ultraviolet advanced oxidation process (UVAOP) treatment

before injection into the high-quality aquifer. After a review

of the legislation, discussions with regulatory agencies, and

exploration of available options, Floridan aquifer recharge

was identified as potentially more cost-effective and

environmentally-friendly direction for the City.

When faced with an imposed reuse mandate, the City of Hollywood (FL) turned to

Hazen and Sawyer to develop a treatment approach that demonstrates emerging

contaminant oxidation without reverse osmosis, which has the potential to greatly

reduce costs and carbon emissions.

Hazen and Sawyer recently completed a custom pilot study to develop an innovative reuse treatment option and help Hollywood (FL) cost-effectively comply with the Ocean Outfall legislation.

nnovations inIndirect Potable Reuse I

HORIZONS SUMMER 2014 3

Due to the brackish quality of the Floridan

aquifer (TDS > 500 mg/L), alternative treatment

processes using ultrafiltration, ion exchange, ozone

and ultraviolet light (UV) based AOPs, as well as

biofiltration, were examined as an alternative to the

full advanced treatment (FAT) approach of RO and UV

AOP that is currently the standard treatment in potable

reuse applications. Prior to use as drinking water, raw

water from the Floridan aquifer requires nanofiltration

(NF) or RO membrane treatment to achieve potable

quality, allowing the City to consider less-expensive

recharge process schemes without redundant RO or

NF membrane treatment. If successfully permitted,

this reuse project utilizing Floridan aquifer recharge

could potentially save the City about $100 million

dollars in capital costs over Biscayne aquifer recharge

and about $800 million in capital costs over irrigation-

level treatment and expansion of the public access

irrigation system.

Based on the specific characteristics of the SRWWTP

effluent and the aquifer water quality, Hazen and Sawyer

developed a customized plan of study to achieve

acceptable emerging contaminant oxidation using treatment

technologies that are more cost-effective and have a smaller

carbon footprint than traditional MF/RO/UV-AOP treatment.

The goal of the pilot project was to demonstrate the ability to

reliably produce water that satisfied primary and secondary

drinking water standards (with the exception of certain

constituents naturally present in the Floridan Aquifer, such as

sodium and chloride) and removed emerging contaminants.

If successful, it would likely define future aquifer recharge

standards for Broward County.

After considering the impacts associated with

Broward County Code compliance, the project team

approached the County with the treatment concept.

Pilot Study Program Objectives and Guidelines

Biscayne

Plant effluent

Floridan

The Floridan aquifer is a deeper, more saline body of water with high levels of total dissolved solids, requiring reverse osmosis membrane

treatment to achieve potable water quality. Recharging the Floridan Aquifer, rather than the Biscayne, means reverse osmosis treatment may

not be needed prior to injection, drastically reducing power consumption, better protecting the environment, and saving the City around $100

million in expenditures.

Sodium Levels, mg/LKey

17.5

0 1,500

1,100835

TDS Levels, mg/L0 5,000

4,5003,500300

- About 1,500 feet deepFLORIDAN AQUIFER

Reuse Injection

AtlanticOcean

ReverseOsmosis Water

PlantConventional

Water Plant SRWWTPhomes

BISCAYNE AQUIFER - About 150 feet deep

Efficient Treatment Saves $100 Million

Indirect Potable Reuse


return to SRWWTP

return to SRWWTP

SecondaryClarifiers

DeepBed Filters

TOC NH4IX IX

IX

Cl2

SecondaryClarifiers

Cl2

H2O2

DeepBed Filters

TOC NH4

UV-AOP BAC

UVBACO3

+-+

-+

-

+-+

-+

-

+-+

-+

-

+-+

-+

-

IX

Pilot Schemes

The Broward County Environmental Protection and

Growth Management Division (BCEPGMD) suggested

that certain water quality requirements for aquifer

recharge may be waived based on demonstration

of reasonable emerging contaminant oxidation. As

a result, the pilot study was designed to meet this

goal using alternative treatment technologies that

are fully protective of the environment, have reduced

carbon emissions, and are more cost-effective, while

being predicated on regulatory waivers for COD, TDS,

chloride, sodium, and phosphates.

The pilot test was conducted for approximately 10

months (i.e., actual operation of the pilot equipment, not

including start-up). Throughout the study period, the

pilot plant operated 24 hours/day, 7 days/week, with the

exception of scheduled monthly equipment cleanings. The

pilot used portable treatment system containers on site at

the SRWWTP, treating secondary effluent from the facility.

From the outside, these pilot systems looked like standard

shipping containers. Inside, they offered advanced

treatment systems that used ozone, ultraviolet light, and

hydrogen peroxide to create an AOP, which enabled the

project team to evaluate and optimize different methods for

treatment with a few clicks of a button.

Results Pilot-scale testing of these novel approaches

demonstrated that an effluent quality that complies with

state regulations and removes emerging contaminants can

be achieved while offering additional benefits to the public

and the environment by way of substantially reduced

costs and carbon emissions.

As summarized in the table on the following page,

both piloted treatment technologies successfully oxidized

emerging contaminants well below the targeted limits.

The pilot test found that both Process Scheme 1

and 2 are viable options for recharge in Broward County

to satisfy the new state reuse requirement. The present

value of the treatment necessary for full compliance with

state recharge regulations is estimated to be $190 million,

while full treatment compliance with Broward County

regulations have an estimated present value of $590

million. However, this pilot testing achieved an effluent

quality that complies with state regulations and removes

yet-to-be-regulated emerging contaminants at a present

value in the range of $290-330 million, which is half the

cost of traditional treatment methods. The annual O&M

costs of the piloted treatment schemes ($6.8-8 million

2 – OzoneThis process scheme includes secondary treated effluent from the SRWWTP followed by deep bed filters (DBF), ion exchange

(IX) for TOC removal, IX for ammonia removal, ozone, biological activated carbon filters (BAC), and UV.

return to SRWWTP

return to SRWWTP

SecondaryClarifiers

DeepBed Filters

TOC NH4IX IX

IX

Cl2

SecondaryClarifiers

Cl2

H2O2

DeepBed Filters

TOC NH4

UV-AOP BAC

UVBACO3

+-+

-+

-

+-+

-+

-

+-+

-+

-

+-+

-+

-

IX

This process scheme included secondary treated effluent from the SRWWTP followed by deep bed filters (DBF), ion

exchange (IX) for TOC removal, IX for ammonia removal, ultraviolet advanced oxidation process (UV-AOP) and biological

activated carbon filters (BAC).

1 – UV/AOP


annually) would also be half of that of traditional treatment

methods ($16.2 million annually). This approach offers

additional benefits to the public and the environment by way

of substantially reduced carbon emissions. Meeting Broward

County standards through traditional treatment would release

an estimated 26,000 tonnes of annual carbon emissions,

while the piloted treatment schemes would release less than

half as much (12-14,000 tonnes).

Future Applications

As growing demand strains existing drinking water sup-

plies and increasingly stringent wastewater effluent standards

lead to more advanced wastewater treatment, indirect potable

reuse is becoming a feasible scenario for more utilities. A ma-

jority of potable reuse schemes in operation or being planned

in the U.S. make use of AOPs and RO to ensure maximum

contaminant removal. This pilot developed two potable reuse

schemes where RO or NF membranes are not incorporated at

the reuse facility, potentially reducing carbon emissions and

saving municipalities significant capital and O&M costs.

The City of Hollywood is currently debating the public

policy implications of various treatment options and their im-

pacts with the appropriate regulatory agencies. Utilization of a

tailored approach to reuse promises a solution that is the most

protective of public health and the environment.

Parameter Current Pilot Effluent Averages (mg/L) Limit Scheme 1 Scheme 2 (mg/L) (UV-AOP) (Ozone)

BOD5 5 2.0 3.4

TSS 5 3.4 3.5

TN 10 7.3 7.9

Nitrite 1 0.7 0.7

TOC 3 1.1 1.1

TOX 200 85.1 82.6

Chloride 250 1,400 1,400

Sodium 160 776 767

TDS 500 3,480 3,460

Phosphates 0.01 1.2 1.2

COD 10 14 16

Red Background: Based on demonstrated emerging

contaminant removal, waivers will be sought from the

Broward County Environmental Protection and Growth

Management Division (BCEPGMD)

$600

$500

$400

$300

$200

$100

0

million

Statecompliance

Pilot technique*

Traditionaltechnique

*Complies with state regulations and removes yet-to-be-regulatedemerging contaminants

Broward Countycompliance

Hazen and Sawyer Pilot TechniqueSlashes Costs...

Excess

12,000

26,000

Carbon dioxide emission (in tonnes) would be cut to approximately half

CO2

Hazen and Sawyer staff constructed and operated the pilot

plant, collecting data for ten months.

...and Carbon Emissions


The Nassau County Department of Public Works

owns and operates the 70-mgd Bay Park Wastewater

Treatment Plant (BPWWTP), which was heavily

damaged during Hurricane Sandy. When faced with

rebuilding the facility, the County decided to capitalize

on the opportunity and proactively prepare the plant

for anticipated future nitrogen removal requirements.

As part of the recovery and rebuild efforts,

the County turned to Hazen and Sawyer to assist

with evaluating and demonstrating innovative

for the Bay Park Wastewater Treatment Plant

Hazen and Sawyer developed an innovative nitrogen removal process

for Nassau County that meets stringent regulations and is estimated to

save up to approximately $1 million/year in chemical costs.

Sidestream Treatment Solutions


technologies that would enable the facility to achieve

nitrogen removal in the most efficient way possible.

While conventional methods were considered,

a comprehensive process evaluation identified

sidestream treatment as a promising alternative.

In this approach, a novel biological process called

deammonification would be utilized to biologically

remove approximately 10% of the total nitrogen at the

BPWWTP. Deammonification is an emerging process

that can reduce the cost of wastewater treatment

for many facilities, enabling an approximately

63% reduction of theoretical O2 requirements, an

approximately 100% reduction of supplemental carbon

requirements, and a significant reduction in biomass

handling requirements when compared to removal

through a mainstream activated sludge process.

A cost evaluation conducted as part of our

research indicated that the BPWWTP would observe

potential savings of approximately $1 million per year

using deammonification by avoiding supplemental

carbon and aeration costs.

Technology Alternatives and Selection

Presently, there are three main technology options

for equipment related to performing sidestream

deammonification, as seen in the table below.

After a careful consideration of the available

technologies, the DEMON™ process was selected

for piloting at the BPWWTP. The DEMON™ process

employs a sequencing batch reactor configuration,

coupled with a hydrocyclone, for the selective

wasting of nitrite oxidizing bacteria and the retention

of anaerobic oxidizing bacteria (Anammox). The

Anammox bacteria are the main biological catalysts

behind the deammonificiation process.

The reactors are filled from a filtrate/

centrate equalization tank and operated in batch

mode. Aeration is followed by mixing and then

sedimentation. The effluent is then decanted from

the sequential batch reactor. Each cycle (fill, reaction,

settle, withdraw) is repeated approximately three

times per day.

DEMON Pilot Testing and Results

Hazen and Sawyer, in collaboration with World

Water Works and Nassau County, piloted the

DEMON™ process at the BPWWTP from August to

November 2013.

The DEMON process pilot, which achieved and

maintained high levels of nitrogen removal throughout

testing, can enable utilities to save over $1 million a

year in chemical costs.

DEMON™ ANITA Mox™ Cleargreen™

Reactor configuration SBR with hydrocyclone MBBR or IFAS SBR

Biomass characteristic floc biofilm floc

Control parameters pH, NH4 loading pH, NH4 loading NH4 loading, aeration

Power consumption (kWh/kg N) 1.16 1.45 - 1.75 Not reported

Design Loading (kg N/m3-day) 0.7 to 0.8 1.2 to 2.0 0.7

Technology Provider World Water Works Veolia/Kruger Degremont


Start-up of the system was accomplished

within 20 days to meet 80% removal of influent

ammonia, and this high level of performance was

maintained for the duration of the pilot. Additionally,

no supplemental alkalinity or carbon was required,

demonstrating that the sidestream deammonification

process is a viable, cost-effective strategy for

nitrogen reduction at the BPWWTP.

As a result of the success of this piloting effort,

we are currently working on a full-scale design of a

sidestream deammonification system for BPWWTP

using the DEMON technology.

Future Applications

Even though the deammonification process is

an emerging technology, opportunities for process

optimization are already being explored. As part

of the Bay Park project, Hazen and Sawyer, in

collaboration with Manhattan College researchers,

developed and utilized an Anammox-specific activity

assay. This assay, which tracks anammox activity

during periods of both high and low activity and can

be applied to other deammonification systems to

compare results, represents a simple and effective

strategy that can be used to directly monitor the health

of the Anammox bacteria in the deammonification

process. It also provides the industry with a first step

toward diagnosing and solving process instabilities

that can arise from dynamic full-scale operation of

deammonification systems.

10

20

30

40

50

60

70

80

90

100

0 10 30 50 70 90

% of NH3 Removed

Days of Pilot Operation

In addition to our nitrogen removal pilot, we are

managing (in joint venture) a major $2.2 billion program to

upgrade the entire Bay Park facility, including:

Overseeing

Assisting

Developing

Utilizing

Building

Establishing

20 design contracts (to 30% completion), 17 major construction contracts, and four major sewer construction contracts

the county with obtaining federal and state funding

extreme weather hardening solutions such as flood walls and raising equipment

advanced wastewater treatment and resource recovery in the rebuilt treatment plant

a state-of-the-art solids train that will realize

significant cost savings

operational excellence goals for reducing energy demand, clean water usage, odors, and city water and sewage usage

Influent Ammonia Removed Overall Program Integrating Desal


Stabilization & Pipe Loop Approach

Increasing populations and strained water supplies

are creating significant drinking water challenges for

communities worldwide. More and more, providers are

having to expand their portfolio of sources to bridge the

gap between supply and demand. While water reuse is

a viable tool for any utility, coastal communities have the

opportunity to turn an abundant natural resource – the

ocean – into a viable potable supply.

As the cost of importing water continues to rise,

desalinated ocean water has become a cost-effective

supplementary water supply for a growing number of

utilities on the west coast of the United States. One utility

pioneering the incorporation of “desal” (desalinated water)

into a drinking water system is the West Basin Municipal

Water District (West Basin), provider of wholesale water

service to 17 cities and approximately one million people in

southwest Los Angeles County. West Basin is an industry

leader in water recycling and conservation and established

a goal of serving 10 percent of the local water supply with

desalinated ocean water by the year 2020.

Water Quality Integration Study

West Basin’s recent Water Quality Integration Study

evaluated the impacts of introducing desalinated water

into the existing potable water distribution system. Hazen

and Sawyer conducted a four-month pipe loop study

with assistance from Separation Processes, Inc. (SPI)

and various technical advisors. The study evaluated

corrosion-related impacts of stabilized desalinated water

and blends with other local sources on different pipe and

household plumbing materials in pilot-scale pipe loops.

Two additional aspects of the testing - disinfectant residual

Influent Ammonia Removed Integrating Desal

Like many coastal utilities in water strained areas, West Basin is studying the incorporation of desalinated water into its potable supply. Hazen and Sawyer recently studied how it can avoid problems in its distribution system.

ROPermeate

Calcite Filter Bag Filter 300 Gallon Storage Tank

AcidChloramines

Potential foradjustments through

recirculation loop

Caustic Soda

Mixer

Pumped into 55-gallon drums at the demonstration pad in blends with MWD and groundwater


stability and disinfection by-product formation - were

investigated both at pilot-scale and through more in-depth

testing in the laboratory by the Metropolitan Water District

of Southern California (MWD).

Prior to introduction into a drinking water distribution

system, desalinated water requires post-treatment. This

treatment involves the addition of some minerals back

into the water to provide a water quality that is non-

corrosive toward distribution system materials. In particular,

desalinated water requires the addition of alkalinity (buffer

capacity), calcium, and pH adjustment. Without post-

treatment, the water can extract metals or cement from

pipes, which can result in regulatory level exceedances,

aesthetic concerns, and infrastructure issues. With proper

stabilization, desalinated water can be integrated into

a distribution system without incident. For this study,

ocean desalinated water generated at West Basin’s Ocean

Water Desalination Demonstration Facility (OWDDF) was

stabilized using calcite contactors prior to testing the water

in the pipe loop and bench-scale studies.

Technical Approach

An initial aspect of this study was the identification

of treatment targets for key water quality constituents.

A literature search and utility survey were conducted

to review the current knowledge and experience on

desalinated water stabilization in terms of water quality

targets for corrosion control. The pipe loop study was

conducted with new cement mortar-lined steel pipes (CML

loops), used unlined cast iron pipes harvested from the

local distribution system (UCI loops), and new copper

pipes with lead solder and harvested brass meters (CU

loops). These pipes and materials represent the different

types of potential materials in the distribution systems

that are susceptible to corrosion if the desalinated water

New Global Desal Capacity since 198012

9

6

3

0

million m3/d

1980 ‘90 2000 ‘00 ‘12 ‘18

estimated*

*data as of October 2013 Source: Global Water Intelligence

6” diameter unlined cast iron pipe (pictured above)

that was removed from a local distribution system with

significant buildup of iron and manganese deposits.

New 4” diameter cement mortar-lined pipe with

fresh cement linings, representing cement most

susceptible to leaching.

New ¾” copper pipe with lead solder (also

representing non-passivated surfaces providing a

worst-case scenario).


has corrosive tendencies. The pipe loops were tested

with stabilized desalinated water, MWD water, a blend of

desalinated water and MWD water (50:50), a blend of MWD

and groundwater (25:75), and a blend of desalinated water

and groundwater (25:75).

Pipe loops were operated on a weekly basis, with fresh

water filled in pipe loop tanks on Day One and recirculated

water discharged on Day Seven. UCI and CML pipe loops

continuously recirculated water for six days, then the

water was replaced on the seventh day. Copper pipe was

operated in a flow-through manner with 0.5 hours of flow,

11.5 hours of stagnation, 0.5 hours of flow and so on for

the seven-day period. First flush samples were collected

after approximately eight hours of stagnation from the

brass meters and, separately, from the copper pipes.

Water in the pipe loop tanks was sampled three times

a week: when the tanks were freshly filled (Day One), in the

middle of the week (Day Five) and at the end of the week

(Day Seven). The freshly filled water served as a baseline

for the weekly testing and also ensured proper blending

was achieved in the pipe loop tanks that required blended

water. Samples from the middle of week were monitored

to characterize chloramine degradation. Samples from the

end of week were monitored for corrosion products.

The pipe loop study continued for four months to allow

evaluation of differences in corrosion observed for the

water sources and blends.

Bench-scale testing was conducted by MWD using

Unlined Cast Iron

Cement Mortar-Lined Steel

Pipe Loop StudyCast Iron | Cement | Copper

Unlined Cast Iron Pipe Loops Cement Mortar Lined Pipe Loops Copper Pipe with Lead/Tin Solder Loops

50 Gallon Tank

100% MWD(Control)

100% Desal(Control)

25% Desal + 75% groundwater

25% MWD+ 75% groundwater

50% Desal + 50% MWD

4 ft. long, 6 in. diameter Discharge

to waste

Duplicate Loop

1

2

3

4

5

6

50 Gallon Tank

100% MWD(Control)

100% Desal(Control)

100% Desal(Control)



50% Desal + 50% MWD

8 ft. long,4 in. diameter

Four 10 ft. long copper pipesjoined by lead/tin solder

Discharge to waste

Discharge to waste

Duplicate Loop

100% MWD(Control)



50% Desal + 50% MWD

Duplicate Loop

1

2

3

4

5

6 6

60 Gallon Tank

1

2

3

4

5

Key Pump Valve Flowmeter Sample Tap Brass Meter


50 Gallon Tank

100% MWD(Control)

100% Desal(Control)



50% Desal + 50% MWD


to waste

Duplicate Loop

1

2

3

4

5

6

50 Gallon Tank

100% MWD(Control)

100% Desal(Control)

100% Desal(Control)



50% Desal + 50% MWD



Discharge to waste

Discharge to waste

Duplicate Loop

100% MWD(Control)



50% Desal + 50% MWD

Duplicate Loop

1

2

3

4

5

6 6

60 Gallon Tank

1

2

3

4

5



50 Gallon Tank

100% MWD(Control)

100% Desal(Control)



50% Desal + 50% MWD


to waste

Duplicate Loop

1

2

3

4

5

6

50 Gallon Tank

100% MWD(Control)

100% Desal(Control)

100% Desal(Control)



50% Desal + 50% MWD



Discharge to waste

Discharge to waste

Duplicate Loop

100% MWD(Control)



50% Desal + 50% MWD

Duplicate Loop

1

2

3

4

5

6 6

60 Gallon Tank

1

2

3

4

5


Copper with Lead Solder and Brass Meter


50 Gallon Tank

100% MWD(Control)

100% Desal(Control)



50% Desal + 50% MWD


to waste

Duplicate Loop

1

2

3

4

5

6

50 Gallon Tank

100% MWD(Control)

100% Desal(Control)

100% Desal(Control)



50% Desal + 50% MWD



Discharge to waste

Discharge to waste

Duplicate Loop

100% MWD(Control)



50% Desal + 50% MWD

Duplicate Loop

1

2

3

4

5

6 6

60 Gallon Tank

1

2

3

4

5



simulated distribution system (SDS) methods to evaluate

chlorine stability and DBP formation. In short, the bench-

scale study evaluated stabilized desalinated water, various

blends of desal with MWD water and/or groundwater,

and MWD water (i.e., the same blends as

pilot tested). The desal water and MWD

water were chloraminated, while

the groundwater was tested with

either chloramines using natural

ammonia or chloramines after

breakpoint chlorination to first

remove natural ammonia.

Results and Findings

For highly tuberculated unlined

cast iron pipe loops, release of

iron and manganese from deposits

was similar for all blends tested. Iron and

manganese concentrations dropped below the

secondary MCLs during the testing (<0.3 mg/L total iron,

< 50 µg/L manganese). Results showed that 100% desal

water or blends of desal with groundwater or MWD water

did not cause higher total iron release compared with 100%

MWD water.

For CML pipe loops, aluminum and pH were monitored

as primary indicators of cement mortar dissolution.

Throughout the testing, the recirculated waters were below

the aluminum secondary MCL of 200 µg/L.; pH increases

were observed for all loops, especially during the first two

months since the pipe surfaces were unsealed. After this

period, pH stabilized around 8.5 -8.6, slightly above pH

levels in fresh waters. Overall, stabilized desal and desal

blends were not more aggressive toward cement mortar-

lined pipes than other blends tested.

For CU pipe loops, the desalinated water alone or

in blends did not show an increased tendency to leach

lead from lead solder or brass meters. Copper and zinc

concentrations in the stagnant water were well below the

action level of 1,300 µg/L for copper and secondary MCL

of 5,000 µg/L for zinc for both copper pipe segments and

the brass meters.

Pilot testing showed that disinfection by products were

very low in 100% desal – both fresh and recirculated waters.

No increase in DBPs was observed for blends compared to

the proportion of the original water quality contributions.

The bench-scale testing conducted by MWD

evaluated chloramine stability at two pH levels,

temperatures, and bromide concentrations. Results

showed that chloramines can be stabilized with a

chloramine contact time of approximately

four hours, with reboosting at that point

before water enters the distribution

system. Overall, replacement

of MWD water with desal in a

distribution system is expected

to decrease TTHM, HAA5, or

iodinated DBP concentrations

in the distribution system.

The results of the pilot

and bench tests indicate that

the introduction of desalinated

ocean water (with appropriate

calcium, alkalinity, and pH levels,

and stabilized chloramine residual)

into a range of typical and representative

distribution system and household materials is not

expected to cause negative impacts on water quality,

corrosion, or disinfection. These pipe loop studies

provided proof that municipalities can safely utilize

desalinated water or blends to supplement their water

supply without sacrificing water quality or damaging their

distribution system.

Water was sampled three times a week: once the tanks

are freshly filled (Day One), once in the middle of the

week (Day Five) and once at the end of the week

(Day Seven).


In May 2002, the Towns of Apex, Cary, and Morrisville

(NC) formally agreed to jointly commission the Western Wake

Regional Wastewater Management Facilities (WWRWMF)

Study to evaluate options for providing long-term wastewater

management services for western Wake County. As a

result of the evaluation, those local governments elected

to proceed with plans for the construction of regional

wastewater management facilities to serve the needs of

western Wake County to the year 2030. The Town of Cary

was designated as the lead agency for the project partners.

Hazen and Sawyer was selected to perform program

and construction management services for the eight major

construction packages that comprise the Western Wake

Regional Wastewater Management Facilities project. The

project includes three pump stations, one water reclamation

facility (WRF), and all the pipes that connect them. The

West Cary and Beaver Creek pump stations move raw

wastewater from the Towns to the new WRF for treatment.

The third pump station, at the WRF site, and a force main

take the treated effluent from the Western Wake WRF to a

discharge point. The discharge of the treatment facility will

also satisfy the terms of an interbasin transfer (IBT) certificate

that requires effluent to be discharged to the Cape Fear River

basin, the source of drinking water for the Project Partners.

Hazen and Sawyer recently completed construction and program management services on a major wastewater project in a growing county in North Carolina, ensuring sufficient treatment levels for decades to come.

Work at the 18mgd treatment plant included construction

of liquid treatment and solids handling facilities,

administrative buildings, and an effluent pump station.

Expanding Population, Expanding Capacity

Four of the eight construction contracts were based on the same site: the treatment plant. Daily coordination was needed to

ensure the projects were constructed in the proper order and without interfering with other aspects of the program.


Construction CoordinationThe eight construction contracts had to be completed

at the same time, and since every facet of the project was

dependent on the others, scheduling management was of the

utmost importance. Seven different contractors were selected

for the eight contracts, providing additional challenges. Hazen

and Sawyer held weekly meetings with these contractors to

facilitate coordination among these contractors and devise

a full construction schedule that accounted for all of the

moving parts. We also developed a scheduling and electronic

document management control system that seamlessly

integrated all WWRWMF contracts.

Four of the concurrent contracts were based on the same

site: the treatment plant. Daily coordination of the various

contractors was required to ensure work got done in the proper

order and without adversely impacting other components of

the project. Our staff also managed coordination between the

various points of overlap among these four contracts, including

shared access roads, interface points between contracts,

traffic control, and equipment deliveries.

Design and Constructability Reviews

The eight different components of the project were

designed by five different design engineers. Since all of the

projects were intended to operate in concert and consistency

between designs was paramount, Hazen and Sawyer utilized

an intensive multidiscipline approach at the outset of the

project to ensure consistency between plans and specs,

coordination between contractors and projects, and optimal

plant performance when completed.

Due to our longstanding relationship with Western Wake

Partners and our facility design expertise, we continued to

improve the third-party design as construction proceeded.

These improvements will result in improved process flexibility

and more cost-effective plant operation upon completion.

We also managed and reviewed all shop drawings, RFIs,

RFPs, change orders, and other submittals to ensure that no

proposed changes would adversely affect plant operations or

another component of the program.

Trenchless construction methods, including jack and bore, were used to install pipelines as part of the project.


Significant Community Outreach

The residential location of the project site required

additional attention to noise mitigation, traffic management,

and environmental compliance. Hazen and Sawyer worked

with stakeholders to provide comprehensive community

outreach, regular status/progress reporting, and regulatory

monitoring to minimize any adverse effects on quality of

life of surrounding residents. Local residents were given

advance notification of all construction activities that could

potentially impact them.

Meetings with community leaders and one-on-one

meetings with residents most affected by construction were

held on a regular basis to ensure open communication and

foster public acceptance. A program website was developed

to provide residents and other constituents with regular

updates, construction photos, and resources. Additionally,

our staff worked directly with the Western Wake Partners

to provide additional related benefits to the community that

included sewer service. As a result of these efforts, minimal

community-related issues arose during construction.

Program Outcomes

“Hazen & Sawyer’s services providing construction

management have been extremely valuable, particularly

with regard to managing the numerous, concurrent

critical schedule milestones on this important project for

the Western Wake Partners,” said E. Alexandra Jones,

engineer with the Town of Cary.

Construction of the facilities began in September 2011,

and the facilities are now complete and in final check-out

and start-up activities ahead of schedule and within the

original project budget. We provided extensive training

to the facility operators, including conducting 15 training

sessions on site. In addition, we are preparing electronic

O&M manuals to help ensure optimal operations long

after we have left the site. As the final component of the

project, we are providing complete start-up, testing, and

commissioning services for the entire system and post

start-up process and energy optimization to ensure these

facilities meet the needs of the Partners going forward.

Hazen and Sawyer assisted the Western Wake

Partners’ extensive community outreach effort that

included regular meetings with the community, the

development of a website about project progress,

and informational materials such as this fact sheet.

“Hazen & Sawyer’s services providing construction management have been extremely valuable, particularly with regard to managing the numerous, concurrent critical schedule milestones on this important project...”

With the project being located in a rural, residential

area, and seven different contractors in the area,

traffic management was critical.

Detailed descriptions of our

AWARD WINNING work

Abstractsfrom ACE, WEFTEC and other conferences from around the globe

Articlesreprinted from industry-leading publications such as WE&T and the AWWA Journal

hazenandsawyer.com

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Innovations in IPR Desal HORIZONS

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